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IC3 is a CD4049UBE from TI too and involved.
ST Versions wasn't working, in voice test mode -> no sound - > trigger was only 500mV
update 28Feb2026: use a Cd4009 Cd4009UBE from texas instruments instead of CD4049, on my 2nd yocto2 from a client was the result better !!
https://www.tme.eu/de/details/cd4009ube/puffer-sender-treiber/texas-instruments/
Build Documents
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All Fles are on github
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